[media] si2168: Fix i2c_add_mux_adapter return value
[media] si2168: Fix i2c_add_mux_adapter return value

In case of failure the return value was always 0. Return proper
error code (ENODEV) instead.

Signed-off-by: Luis Alves <7367d521136de37f3b1fafde9cc7163633044762@gmail.com>
Signed-off-by: Antti Palosaari <293134fe763ce2d9d8609280ea107c73cbd2eb86@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <0cae1d1e981e84d16b82ca3d17be8a7f826608d3@samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs